If you are feeling unwell with fever, body aches, and other symptoms, you may be wondering what is making you feel so unwell. Is it seasonal influenza (commonly called the flu)? Or could you have COVID-19? While the two diseases share many similarities, there are some differences.
Path to better health
Both COVID-19 and the flu are caused by viruses. But they are caused by different viruses. COVID-19 is caused by the coronavirus, SARS-CoV-2. Coronaviruses have been around for a long time and can cause the common cold. The flu, on the other hand, is caused by the influenza virus. This is a seasonal virus with two types: Influenza A and Influenza B.
You can get COVID-19 and the flu in a similar way. When a person talks, sneezes or coughs, small invisible particles leave their mouth and nose and travel through the air. These particles are where the virus can live. If you breathe in these particles, the virus is inside your body and can make you sick. Also, if particles get on your hands and then you touch your mouth, nose, or eyes, you can get sick. This is why it is so important to wash your hands frequently.
COVID-19 is much more contagious than the flu. That means it passes more quickly and easily from one person to another.
People at higher risk
While anyone can get COVID-19 and the flu, some groups of people are at higher risk of getting sick. For both COVID-19 and the flu, adults over 65, people who are pregnant, people with lung disease, heart disease, or diabetes are at higher risk. Read more about the risks of the flu for people with chronic illnesses.
Children are also at risk of contracting COVID-19 and the flu.
Symptoms
COVID-19 and the flu have many of the same symptoms, including:
- Fever
- Cough
- breathing problems
- extreme tiredness
- Sore throat
- Nasal congestion
- Body pains, including headache.
- Diarrhea
- Vomiting
You may also lose your sense of smell or taste if you have COVID-19.
COVID-19 and the flu can cause serious illness and complications that require hospitalization. If you have any of these symptoms, contact your doctor immediately. They can diagnose what illness you have and give you advice on what to do next.
How long have you been sick?
It is possible to spread COVID-19 and the flu to others before you even know you are sick. If you have COVID-19, you can spread the virus 2 to 3 days before you have symptoms. Once symptoms start, you are likely contagious for 10 days. It is important to stay away from other people during this time to prevent them from getting sick. If you are around someone who has COVID-19, it may take 2 to 14 days for you to develop symptoms.
With the flu, you can spread it 1 day before your symptoms start. Once you have symptoms, you are contagious for up to 7 days. This time may be longer for children and older people. If you are exposed to someone with the flu, it may take 1 to 4 days for you to develop symptoms.
People tend to be sicker for longer with COVID-19 than with the flu.
Evidence
There are different tests that can confirm if you have COVID-19. Some tests require you to place a cotton swab in your nose. The end of the swab collects a sample from the nasal cavity because that is where germs live. The swab is then sent to a laboratory for testing. The swab can also be used for a rapid antigen test; However, you may need to confirm a positive or negative result with a laboratory test (PCR) if you still have symptoms or need a negative test to return to school or work. A saliva test may be offered and at-home tests are also available (without a prescription). Be sure to check that the test is FDA-cleared before purchasing.
If your doctor thinks you have the flu, he or she may perform one of two tests. One test involves inserting a swab into the nose. This swab will be sent to the laboratory for testing. The other test involves collecting a sample from the back of the throat. It will also be sent to the laboratory for analysis. There are also rapid tests available for the flu.
Laboratories have also developed tests that can detect both the flu and COVID-19. Talk to your doctor to see if they are available in your area.
Treatment
COVID-19
Three COVID-19 vaccines were initially developed for use in the United States during the pandemic. However, in September 2023, the CDC strongly recommended that everyone over 6 months of age receive one dose of the updated 2023-2024 version of the vaccine. People 65 years of age and older will be able to receive a second dose of the updated vaccine.
If you have not received the COVID-19 vaccine in the last 2 months, get an updated vaccine to protect yourself during the fall and winter.
Safety and efficacy data have been collected on more than 220 million people who have received at least one dose of vaccines. Some rare side effects have been seen, but overall the vaccines are safe and effective in preventing serious illness, hospitalization, and death.
These vaccines do not give you COVID-19 and do not cause complications during pregnancy or reduce fertility.
If you have COVID-19, a treatment medication your doctor may prescribe is nirmatrelvir/ritonavir (brand name: Paxlovid). It is an antiviral medicine to prevent people from becoming so sick from COVID-19 that they need to be hospitalized.
Flu
There is a vaccine you can get to help protect you against the flu. It is given as an injection in the arm. The American Academy of Family Physicians recommends that everyone over 6 months of age get a yearly flu vaccine, unless otherwise directed by their doctor. If you get the flu, there are medications your doctor can prescribe to help relieve your symptoms.
The flu vaccine does not give you the flu.
recovery time
If you have had COVID-19, it may take you a long time to recover or weeks before you feel like yourself again. For some people, it can take months (aka long COVID). Talk to your doctor if you have symptoms that continue, as there are options to manage these ongoing symptoms.
People who have had the flu usually feel much better about 2 weeks after getting sick.
Things to consider
COVID-19 and the flu share many complications. These include pneumonia, respiratory failure, kidney failure, and blood infections. These diseases can also worsen existing conditions, including heart problems, lung problems, and diabetes. In severe cases, both diseases can lead to death.
If you have COVID-19, you may also develop blood clots in your legs, lungs, heart, or brain. Your chances of experiencing these side effects increase if you have heart disease, lung disease, or diabetes. Some children develop multisystem inflammatory syndrome. This is a serious condition, but it is not very common.
If you have had the flu, you may develop a sinus infection or ear infection. You can also get pneumonia, which can be serious. Serious side effects are more common in people younger than 5 years old or older than 65 years old, pregnant, or who have asthma, diabetes, or heart disease.
Resources
Familydoctor.org: Flu Prevention
